We explored Q-switching mechanism for the newly proposed Tm/Ho composite laser via developing a hybrid resonator for separating the intra-cavity Tm laser modulated by the saturable absorber(SA).With a Cr:ZnSe SA,succe...We explored Q-switching mechanism for the newly proposed Tm/Ho composite laser via developing a hybrid resonator for separating the intra-cavity Tm laser modulated by the saturable absorber(SA).With a Cr:ZnSe SA,successful passively Q-switching process with the maximum average output power of 474 mW and the shortest pulse width of 145 ns were obtained at the pulse repetition frequency of 7.14 kHz,where dual wavelength oscillation in both 2090 nm and 2097 nm was observed.This work provides an effective way for a direct laser diode(LD)pumped Q-switched Ho laser,which is compact and accessible.Furthermore,the current SA could be replaced by the 2D materials with broadband saturable absorption such as topological insulators or transition-metal dichalcogenides for seeking novel PQS lasers.展开更多
Suppose that G is a finite group and H is a subgroup of G. H is said to be s-quasinormally embedded in G if for each prime p dividing │H│, a Sylow p-subgroup of H is also a Sylow p-subgroup of some s-quasinormal sub...Suppose that G is a finite group and H is a subgroup of G. H is said to be s-quasinormally embedded in G if for each prime p dividing │H│, a Sylow p-subgroup of H is also a Sylow p-subgroup of some s-quasinormal subgroup of G; H is called c^＊-quasinormally embedded in G if there is a subgroup T of G such that G = HT and HCqT is s-quasinormally embedded in G. We investigate the influence of c^＊-quasinormally embedded subgroups on the structure of finite groups. Some recent results are generalized.展开更多
基金We are grateful for financial supports from National Key Research and Development Program of China(Grant No.2017YFB1104500)Natural National Science Foundation of China(NSFC)(Grant No.61875200)China Postdoctoral Science Foundation(Grant No.2018M642575)。
文摘We explored Q-switching mechanism for the newly proposed Tm/Ho composite laser via developing a hybrid resonator for separating the intra-cavity Tm laser modulated by the saturable absorber(SA).With a Cr:ZnSe SA,successful passively Q-switching process with the maximum average output power of 474 mW and the shortest pulse width of 145 ns were obtained at the pulse repetition frequency of 7.14 kHz,where dual wavelength oscillation in both 2090 nm and 2097 nm was observed.This work provides an effective way for a direct laser diode(LD)pumped Q-switched Ho laser,which is compact and accessible.Furthermore,the current SA could be replaced by the 2D materials with broadband saturable absorption such as topological insulators or transition-metal dichalcogenides for seeking novel PQS lasers.
基金This work was supported in part by the National Natural Science Foundation of China （Grant No. 11071229） and the Natural Science Foundation the Jiangsu Higher Education Institutions （Grant No. J0KJD110004）.
文摘Suppose that G is a finite group and H is a subgroup of G. H is said to be s-quasinormally embedded in G if for each prime p dividing │H│, a Sylow p-subgroup of H is also a Sylow p-subgroup of some s-quasinormal subgroup of G; H is called c^＊-quasinormally embedded in G if there is a subgroup T of G such that G = HT and HCqT is s-quasinormally embedded in G. We investigate the influence of c^＊-quasinormally embedded subgroups on the structure of finite groups. Some recent results are generalized.
